As for a conventional vacuum cleaner, there is provided a vacuum cleaner having a dust separation unit, a pleat-shaped filter for capturing fine dust particles contained in the air that has passed the dust separation unit, a gear rotated in relation with a winding operation of a power cord and protrusions installed on the gear. In this vacuum cleaner, while the power cord is being wound, the gear is being rotated therealong to thereby make the protrusions rotate together. The rotating protrusions keep making hard contacts against pleats of the filter to thereby impart rotational motions to the rear surface of the filter as well as vibrations to the pleats, wherein the vibrations make dust particles attached to the filter be dusted off therefrom. (e.g., see Japanese Patent No. 3490081)
However, for such a configuration of the conventional vacuum cleaner, even though dust particles are accumulated on a surface of the filter in an opposite direction of an air flow, since vibrations are applied to the filter in a direction perpendicular to the pleats, i.e., in a direction perpendicular to the air flow, a dust removal efficiency becomes deteriorated. Further, since the vibrations are directly applied to the filter by the protrusions, the filter needs to be made strong, thereby increasing cost thereof.